1. Field of the Invention
The present invention relates generally to an apparatus for setting a garment fastener, such as a snap fastener, a button or an ornament, to a garment fabric, and more particularly to such a button setting machine having a device for indicating a correct location in alignment between a punch and a die of the button setting machine.
2. Prior Art
Various button setting device are known in which a pair of fastener elements is supported on a lower or die unit and an upper or a punch unit, respectively; a garment fabric is positioned between the upper and lower units with the aid of an indictor; and a punch of the upper unit moves toward a die of the lower unit to join the two fastener elements together in clinched condition with the garment fabric sandwiched between the two fastener elements.
U.S. Pat. No. 3,964,661, issued June 22, 1976 discloses one such button setting machine which includes an optical indicator constructed to produce a light spot on a garment fabric at a position where a pair of fastener elements is to be attached. The indicator comprises a light source fixed to a machine frame for projecting a horizontal light beam, and a mirror unit or reflector supported on the forward end of a slide bar so as to reflect the light beam downwardly at a 90.degree. angle, the slide bar being reciprocably movable to advance one of the fastener elements below a punch of an upper unit. When the slide bar is fully advanced with the one fastener element carried on a forward step of the slide bar, the reflected light beam passes along a common vertical axis of the two fastener elements and hence the punch and a die. Since the mirror unit reciprocates in unison with the slide bar for a relatively long distance, the indicator as a whole requires a relatively large area for installation. Consequently, the button setting machine becomes large as a whole. Another disadvantage is that the mirror unit has a downwardly directed projection or pointer defining a channel for the passage of the reflected light. The projection is likely to interfere with the garment fabric while being set between the punch and the die with the result that positioning operation would be rendered tedious and time consuming. The prior indicator has another disadvantage in that correct positioning of the garment fabric is difficult to achieve when the garment fabric has the same or similar color as the light beam.